This invention generally relates to a counterpulsation device and more particularly to a counterpulsation device that operates without the use of compressed air.
Various counterpulsation devices are known and used in the medical field. Counterpulsation devices typically include inflatable cuffs that are placed about selected portions of a patient's body. The inflatable cuffs are typically placed about the calves, thighs and buttocks of a patient. The cuffs are inflated sequentially in a distal to proximal order during diastole. The inflation of the cuffs is timed to provide a second, pressurized pulse of blood flow to all organs above the buttocks cuff when the heart is normally resting between beats. The extra pulse of blood flow has been demonstrated to relieve angina pectoris, to raise cardiac output thereby improving the perfusion of organ beds and to enhance renal, cardiac and cerebral circulation.
In typical arrangements a compressed air source is used to inflate the cuffs and a vacuum pump is used to evacuate the cuffs as needed.
The currently available counterpulsation systems have several shortcomings and drawbacks, mainly because they require the use of compressed air. Compressed air is disadvantageous because it must be carefully managed or it introduces potential problems. Systems using compressed air can become overly pressurized because of a malfunction or blockage in the compressor or an associated accumulator. Overly high pressure conditions must be minimized to avoid subjecting the patient to excessive pressure when inflating the cuffs. Under extreme circumstances, excess pressure buildup introduces the possibility of having a portion of the system, such as a hose or the compressor housing, rupture unexpectedly.
Typical compressors also render conventional systems undesirably noisy, which makes them less than ideal for a hospital or clinic setting. The compressors and reservoirs are also relatively large and cumbersome, which decreases their ability to be readily relocated. The compressed air systems also require components such as vacuum pumps, which introduce additional cost, noise, complexity, and further maintenance issues.
Conventional systems require frequent maintenance because filters and other components must be replaced, especially in a counterpulsation application where the overall machine may be used continuously for many hours. Additionally, compressed air introduces the possibility of condensation build up within the system, which can interfere with proper valve, cuff, and other component operation to further exacerbate the maintenance issues.
All of the above drawbacks contribute to a major shortcoming of conventional systems, which is that they are not portable and useable in different clinical or hospital settings. Another drawback associated with some of the available systems is that they are not versatile enough to provide counterpulsation therapy for a wide enough variety of applications.
There is a need for a counterpulsation device that provides the capabilities of the pressure driven systems that are currently available while having the advantage of not including the use of pressurized or compressed gas. This invention overcomes the shortcomings and drawbacks discussed above and provides a system that is versatile in administering counterpulsation therapy without the use of pressurized or compressed air.